Is it normal to bite my nails, toes, skin and scabs?

I bite my nails. I bite my toes. I pick my scabs and eat them. I bite the loose skin around my toes and nails and eat that and I chew my bitten off nails into dust in my mouth and swallow. Sometimes I'll use the large nail pieces i bite off to get gook out from in between my teeth.

I don't bite my nails or toes if I think they are too dirty, but I don't think i can ever stop as I will do it without thinking. Is this normal? I've also gotten several minor infections and have always done the lancing myself.